linq Standard Query Operators Conversion Operations
Example
Conversion operations change the type of input objects.
AsEnumerable
Returns the input typed as IEnumerable.
Method Syntax
// AsEnumerable
int[] numbers = { 1, 2, 3, 4, 5 };
var nums = numbers.AsEnumerable();
// nums: static type is IEnumerable<int>
Query Syntax
// Not applicable.
AsQueryable
Converts a IEnumerable to a IQueryable.
Method Syntax
// AsQueryable
int[] numbers = { 1, 2, 3, 4, 5 };
var nums = numbers.AsQueryable();
// nums: static type is IQueryable<int>
Query Syntax
// Not applicable.
Cast
Casts the elements of a collection to a specified type.
Method Syntax
// Cast
var numbers = new object[] { 1, 2, 3, 4, 5 };
var nums = numbers.Cast<int>();
// nums: static type is IEnumerable<int>
Query Syntax
// Use an explicitly typed range variable.
var numbers = new object[] { 1, 2, 3, 4, 5 };
var nums = from int n in numbers select n;
// nums: static type is IEnumerable<int>
OfType
Filters values, depending on their ability to be cast to a specified type.
Method Syntax
// OfType
var objects = new object[] { 1, "one", 2, "two", 3, "three" };
var numbers = objects.OfType<int>();
// nums = { 1, 2, 3 }
Query Syntax
// Not applicable.
ToArray
Converts a collection to an array.
Method Syntax
// ToArray
var numbers = Enumerable.Range(1, 5);
int[] array = numbers.ToArray();
// array = { 1, 2, 3, 4, 5 }
Query Syntax
// Not applicable.
ToList
Converts a collection to a list.
Method Syntax
// ToList
var numbers = Enumerable.Range(1, 5);
List<int> list = numbers.ToList();
// list = { 1, 2, 3, 4, 5 }
Query Syntax
// Not applicable.
ToDictionary
Puts elements into a dictionary based on a key selector function.
Method Syntax
// ToDictionary
var numbers = new int[] { 1, 2, 3 };
var dict = numbers.ToDictionary(n => n.ToString());
// dict = { "1" => 1, "2" => 2, "3" => 3 }
Query Syntax
// Not applicable.
